Step 30: Make the Plastic Door

Step 31: All done!

The completed dome

Hello! Hello! We are from YES-2-Tech, part of a program called Youth Exploring Science (YES) at the Saint Louis Science Center, funded by the National Science Foundation as part of their ITEST program (Information Technology Experiences for Students and Teachers). The YES Program is dedicated to providing the opportunity for teens who face multiple risk factors to learn job, school and life skills. As YES-2-Tech Teens, we teach math and science skills to community youth, design and build geodesic dome greenhouses, work with technology and other activities. In addition, we give presentations to large companies to explain them the purpose and progress of the YES Program.

Working and building the domes has been exciting, but also very beneficial. We traveled around St. Louis teaching kids and adults about the purpose and functions of the greenhouses. Also, we supervised the building of domes at different community centers. With a geodesic dome greenhouse, you can extend the growing season of your plants and protect them from the harsh weather outside.

Greenhouses and how they work:

Here's what we learned about why our dome (and other greenhouses) help plants live for a longer season:

Plants germinate (sprout) from seeds and grow through their life cycle depending on light and soil temperature. We couldn't do much about how much the sun was shining, but our dome made the air, and the soil in the dome warmer than outside the dome. From what we saw, it seems that growing season depends more on soil temperature than light, because some of our tougher plants like cabbage and lettuce kept growing in our dome most of the winter. They slowed down a lot, though.

But we wanted to know, why is it so hot inside??? We can tell a difference when we step inside right away, even though the plastic is not that thick. It's much warmer and the air feels sticky sometimes. It feels really nasty in there sometimes in the summer. There are 2 main things that our dome does to help the temperature stay warmer than the outside air.

1. The air inside the dome is separated from the air outside of the dome.2. The clear (or semi-clear) skin lets light energy in, but traps heat energy.

Even though our dome skin is thin, it keeps the air inside the dome from mixing with the outside air when the wind blows, or a bus drives by. When the sun shines on the dome, lots of the high-energy light can come through the skin. Light goes through space in waves, and the light that helps us see can go right through clear objects, like glass or our dome skin. When the light bounces off the ground inside the dome and plants and the tools, it loses some of its energy. That means that the waves that bounce off can't move as fast as the waves that came into the dome, and they get trapped inside the skin. So while the sun shines, the dome gets hotter and hotter as the energy from the sun gets trapped. And this hot air can't mix with all the other air outside, and level out. That's why it feels so different in the dome. We feel it right away. It's nice in the wintertime, but when it gets hot, we start sweating right away when we walk in.

At night, when it is colder, the air in the dome has to cool off before the ground can start getting colder. We buried a digital light and temperature reader in the middle of our dome, and also hung one up in the air on a string using a pipe cleaner to make a hook. We noticed that the air got colder, then the ground got colder. Also, when the air warmed up, the ground got warmer too.

The hotter air in the dome also means that the air is more humid. Humidity means that there is more water in the air, and it can make it seem even hotter than the real temperature. That's why we seal the wood for the dome real carefully. All the water in the air can make the wood get moldy and rot. When we open our vent flaps all the way, it gets cooler fast. The hot air rises out of the vents, and mixes with the outside air. The water in the air also leaves too, and it feels much better in there. We always see little drops of water by the vents when they are closed. That's because the water comes out of the air when it is near the colder air.

Last thing: We want to warn people who think they can grow anything they want all year round. You can try, but you will end up killing a lot of plants (like we did in our first year dome). There are plants that are good for planting in the cold season, like all the plants in the cabbage family. Their family name is Arabidopsis, so if a plant has that in its scientific name, it is probably good for putting in your dome in the fall.

If you decide to use our instructable and make your own dome, we want to know what you planted!!!!! We grow food for people who can't always buy food on their own. We also go to different community groups and build new domes for them. We are getting pretty good at making these, which is why we thought we would share our experience with everybody. How hot does your dome get? What did you add to make our dome even better? Please let us know.

Your Friends, YES-2-Tech Teens from the Youth Exploring Science Program

3) Once you have all of your strips cut, you will use a vise to bend the pieces. Each bend should be approximately a 25 degree angle. On the strips that have ten holes, bend them twice, at the fourth hole from each end. Do this for all ten strips. For the seven-hole strips, bend them once, at the second hole from one end.

4) Once you have all of the pieces bent, you will assemble them. Attach two of the seven-hole strips to the middle (fifth hole from either side) of the ten-hole strips. Place the seven-hole strips on top of each other. Then, using a bolt and a nut, connect them together. You do not need to fully tighten the bolts at this time.

5) Repeat step four until you have a total of ten connectors.

Step 6: 5-Way Connectors

1) Begin by cutting thirty strips that have seven holes each.

2) Once you have all of these strips cut, use a vise to bend the pieces after the first hole from one end. Make 25 degree angles on all bends. You must do this for all thirty strips.

3) Once all of your strips have been bent, it is time to assemble them. Line up the first hole for five of the strips and connect them with a bolt and nut. For assistance on how they should be assembled, refer to the picture.

4) Repeat step three until you have a total of six connectors.

Step 7: 6-Way Connectors

1) For the 6-way connectors you will need to cut twenty-seven strips that have thirteen holes each.

2) Once you have all of the strips cut, you need to bend them using a 25 degree angle. Bend at the fourth hole from each end (leaves five holes in center space). You will bend each strip twice. Do this for all of the strips.

3) Assemble them by connecting them at the center hole (the seventh hole) with a nut and a bolt. Do this for all nine of the connectors. Once you have all of these steps completed, you are finished fabricating the connectors.

Step 8: Make the Pentagons

5-way connectorUsing your drill with a screwdriver attachment, fasten one arm of a 5-way connector to a 42" (A) piece of wood using two screws (with the washer around each of the screws). Look at the picture below for the placement the screws. Once you have your first "A" piece of wood attached, you will repeat this step for the remaining four arms of the 5-way connector. Repeat for all five 5-way connectors.

Step 9: Adding the 4-way connectors

Next you will attach two 4-way connectors to the assembled 5-way connectors and A pieces. Put a washer around the screw (two screws go in each leg), then attach one 4-way connector to one leg at the bottom of the pentagon and attach the other 4-way connector to the other leg at the bottom. For more help, look at the diagram below.

Step 10: Adding the 6-way connectors

Next you will attach two 6-way connectors. Put a washer around the screw (two screws go on each leg) then attach one arm of one 6-way connector to the top of "A" piece of the pentagon and another 6-way connector to the left "A" piece of the pentagon. There will be one "A" piece that does not have a connector. The diagram shows the placement of the 6-way connectors.

Step 11: Attaching the "B" pieces

Attach one 48" "B" piece of wood between each outside connector. Be sure to install two screws and washers for each piece of wood. For more help, see the diagram. There will be no connector on one of the corners of the pentagon.

Step 12: Finish the pentagons

Repeat the previous few steps to complete the other four pentagons. You will have 5 pentagons when you are done.

Step 13: Connect the Pentagons

To connect the pentagons to each other, connect the 6-way connector on the left side of the pentagon to the right side of another pentagon without a 6-way connector. Repeat all the way around until each pentagon is connected. There will be ten "A" pieces connected around the middle of the pentagons.

Step 14: Connect The Bottom of the Pentagon

Now attach "B" pieces between each pentagon at the bottom of the dome using the two 4-way connectors. Repeat until there are ten sides on the bottom of the dome.

Step 15: Connect The Top of the Pentagon

At the top of the pentagons, attach a "B" piece to the 6-way connectors between each pentagon. Repeat until the five "B" pieces connected at the top of each pentagon form a pentagon.

Step 16: Preparing To Make the Roof

First, pick a pentagon most convenient to where you want your door. Then disconnect the 5 internal legs ("A" pieces) with the 5-way connector from the external connectors (4- and 6-way) on each leg. The five legs that are disconnected will remain attached to a 5-way connector and make a star shape. This will be used to make the roof and the open pentagon will be used to make the door.

Step 17: Attaching The Roof

Connect the ends of the legs to the last available 6-way connectors at the top of the dome to form the roof.

Step 18: Tighten all the Connectors

Put one socket wrench on the nut side and one socket wrench on the bolt and tighten up all of the connectors on the dome.

Step 19: Making the Door Frame

Since there are variables that affect the exact dimensions of your completed dome, making the door is a field-engineering task. Measure a piece of wood that will be use to construct the side of the door. Start at the bottom corner of the open pentagon where the 4-way connector is and go straight up until you are touching the top leg of the open pentagon. Mark the wood were it touches the top leg pf the pentagon (see photo below). Repeat this step on the other side.

Step 20: Connect the door frame to the dome

After you mark the piece of wood, cut it at an angle so that it fits the pentagon flush against the top piece of wood. Attach the cut piece to the 4-way connector at the bottom of the pentagon. Use a 3" screw to attach the piece of wood from the top of the pentagon where it fits against the wood. This will hold your door frame together. Repeat this step on the other side.

Step 21: Adding the top of the door frame

Next, measure another piece of wood to create the top part of the door. To do this, hold a piece of wood at right angles to the tops of your two parallel door pieces. Mark the spots that will allow you to connect it to the "B" pieces of wood at the top of the pentagon. From the outside of the pentagon, use 3" screws to attach this piece where it fits against the top of the pentagon and the other door pieces.

Step 22: Adding the side supports

Next, measure a piece of wood that goes from the 6-way connector at the side of the pentagon to the piece of wood that makes one side of the door (see photo below). Screw the piece of wood into the connector and into the piece of wood that it touches. This step adds support to the door. Repeat this step on the other side of door.

Step 23: Adding the top support for the door

The last step of constructing the door is to measure a piece of wood from the top 6-way connector to the top part of the door, cut it and attach the wood to the connector and the door (see photos below).

Step 24: Make a Rebar Bender

Now it time to anchor your dome to the 12' X 12' area where you have cleared the grass. You will use twenty pieces of bent rebar to anchor your dome into the ground.

To see a visual of how to make a rebar bender (jig) and bend the rebar to hold down the dome, visit this website:

www.monkeyc.org/dome/d-gaskets.html

Step 25: Anchor The Dome To The Ground

With your drill hammer (small sledge hammer), hammer two pieces of rebar over each "B" piece into the ground. There are ten sides to the bottom of the dome, so you will use twenty pieces of rebar to hold it down.

Step 26: Cover the Dome with Plastic

Cut out a large sheet of plastic, about 6 to 7 feet long. Cover a section of the dome with the plastic. Start from the bottom and work your way up. See photos below.

Step 27: Staple Plastic and Cut off Extra Plastic

Pull the plastic tight over one triangular section of the dome. Staple just enough to attach the plastic to the wood on each leg of the triangle. Then go back and staple the plastic to each leg of the triangle, stapling about two inches apart. As you do this, continue to smooth the plastic to get the wrinkles out. It helps to fold the excess plastic on top of itself as you staple it onto the wood. Continue by covering as many triangles as you can until you have used up the plastic sheet. When your first section of plastic is securely attached, cut off any excess that does not completely cover a triangular section of the dome.

Step 28: Keep Adding Plastic Until Finished

Repeat the process until the dome is covered. You will need to put a ladder inside the dome to staple the plastic onto some of the top parts (see photo).

Step 29: Add the vent

You'll most likely need a ladder inside the dome for this step. Place the ladder on the ground under the top of the dome. Cut along one leg of any triangle at top of the dome (see photo). This will create a vent that will allow air to circulate and help regulate the temperature in your geodesic dome greenhouse.

Step 30: Make the Plastic Door

To make the plastic door area for the dome, put a sheet of plastic on the door frame, cut it through the middle into two symmetrical halves, staple the plastic onto the frame, then trim the excess plastic hanging from the frame.

Brilliant. Great work!! I'm curious about wind though. Do you find that wind causes problems through that open portal? I mean in a ballooning fashion that tears the plastic off the beams? I had that issue from a small spot.

Another alternative for the connectors, is PVC pipe sections, and plumbing strap. You have to cut the end of the board at an angle, but it makes a fairly strong connection. The pipe is a little big in these pictures, optimally, it should be just big enough for all the pieces of wood to fit around.

Hmm... I've been wanting to make something like this for a long time, but I have two problems: (1) wood is expensive (and I'm 13) (2) I'm absolute carp at woodwork. So, is there any other material I could use? PLEASE?

hey dude, just find someone that knows how to do it and learn from them! take woodshop in highschool or something. i was lucky to have my dad who is experienced in carpentry, electrical work, plumbing, and car work. so i learned a lot from him. now im the leader of the fabrication/build and electronic sub teams on my robotics team. check out the bot we made :D http://www.youtube.com/watch?v=lrm1GxsA6hY (check 8-12. up until then i did all the work on building it ;D ) (i designed a lot of the frame and such, then cut it out and welded it with a TIG machine) if i can figure out how to tig weld aluminum in about a week to make that, im sure you can quickly master woodworking ;D just never give up! because you never truly fail until you give up :3 something else you might be able to use that'd be a bit easier than wood is PVC. its pretty cheap (not sure if its cheaper than wood or not) you can just come up with a design, get some tubes, some lil joint connectors and pop it all in place! :D then you can disassemble it and such (maybe use 2 end connectors and some zipties to hold it together?) also, if you happen to have one of those dome camping tents with 4-6 tent poles. just put those in the basic form of the dome, then put plastic over them instead of the tent ;D

Nick, don't be discouraged by woodworking. It's tough at first. When I was your age I said the same thing. I came back to it 30 years later and found that with a bit of patience, willingness to learn and a lot of cheap MDF that I'm a pretty decent woodworker. I wish I would have had the patience to keep trying I would be a master carpenter by now.

I can imagine your difficulty, being only equipped with fins, and the tendency of wood to float out of your aquatic environment. "I'm absolute carp at woodwork "... Sorry about that. I don't usually poke fun at other's typos (I actually almost just typed "fin" instead of "fun" back there, for real and no joke). Myself being at best a four finger hunter and pecker (Man, that sounds rude!) and mine own typographical errors probably being legion. I reiterate, this is not a dig, but merely a giggle. Seriously, I suggest keep bashing at the wood. Skill will improve with time. Many "professional" homebuilders (I use that term loosely) have committed more sins and atrocities with wood, than you would care to imagine. As to the expense, if you go to the lumberyard and ask for "strapping" rather than "framing" lumber, it is somewhat less dear.

I think threecheers summed it up nicely! "Absolute carp" describes the syndrome perfectly :] And I agree with you packrat: I was tempted to verbalise my smile too. Still, it happens to the best of us: this is from Jomsom, Nepal and nicely balances threecheers' typo (pink highlight is mine).

If you're concerned about the price of wood, you can try pallets. We have a couple of personal-water-craft and motorcycle places around here that have piles of pallets they just give away, or else they have to pay to have them hauled off. The nice thing about free wood, is that mistakes are cheap. Another advantage to the geodesic domes, is that shorter pieces of wood can be used when building at higher frequencies. I once built a storage building entirely out of scrap wood. It was a 4 freq. 16' dia dome, no strut was longer than 30". (Lot more labor in a higher frequency though)

Free wood rules! A couple other good sources include: 1) Old box springs from beds. Not all beds have 'em, but those so equipped are a source of eight or so nice one by fourish planks. There's some effort and a mild degree of danger in the dismantling process, but it's fun and rewarding. I just built a rain barrel stand out of such lumber. 2) Roof truss manufacturers offcuts. Most of these places have a bin or pile marked "FREE WOOD" You can get loads of chunks of truss grade wood, many with nice angles already cut in them. Most are pretty short however. If you're lucky, you can score some of the banding support pieces (used to keep the steel strapping from digging into the bundles of lumber during shipping.) They usually look kinda rough and have a 1" or so wide channel routed into one side to hold the strap. They are crazy strong and usually a good three or four feet long.

pvc, rebar, steel pipe... There are designs for domes that use those materials which you've prolly already sussed out in this website, but in case you've been too bz 2 research. http://www.instructables.com/id/How-to-build-a-PVC-geodesic-dome/ Many hardware stores n construction supply stores can cut the pvc for you. Get free or extremely cheap scrap pvc at garden centers, construction sites, dump sites, and Habitat For Humanity type centers during spring or fall seasons. Those seasons are also best times to get the other hardware needed for the project. Craigslist often has them in FREE listings, however, you have to be diligent in your searches, be the first contact, and be available on the fly to pick the stuff up esp. if they're CURB ALERT listings. Most burners use pvc \<>/ esp. cuz it's lightweight and durable.

I've seen domes made with 3/4" conduit tubing. This is cheap and it's galvanized metal. The pipes were cut to whatever length, and the last 2 inches or so was flattened and had a single hole drilled through it. Pipes were connected via a bolt through the holes. Super simple and elegant. And moveable too!

Well, the design keeps snow from building up. Most of it will slide down and collect around the base as soon as it reaches critical mass and can no longer fight the steepness of the dome design. Northern Minnesota gets about 81" of snowfall annually with their deepest snow base month being January with fall rates in the upper 50s. Spread over a month, that's not much depth hitting the dome. If you're worried then periodically sweep off the top of the dome that month. It's phenomenally rare for Lake Superior to create large lake-effect snowfall so if you're worrying about six foot overnight blizzard dumps then expect that to occur every 100 years or so, if that. The most snowfall occurring in a 24 hour period in the northern region of your state was 36 inches on January 7, 1994 in Lake County, MN. That's nothing to sweat about for a dome greenhouse like this. I live in Denver, CO and we see near the amount of snowfall you do. We have these domes all over Colorado. Even in the high country where snowfall is greater. Just be sure to attach the plastic cover as tightly as you can and reinforce seamlines and replace the staples from time to time. Also, there are more rounded green house designs you can use; houses that have less sharp angles. :) \<>/

build one big enough to cover a fig tree (up here in the great frozen snowy North Shore (long Island), and you got have a nice snow cover. Just use blue tarp material and pack straw and mulch all around the trimmed bundled tree. Then in spring remove the color tarp put clear tarp. remove the stakes pickup over the tree move to a spot and gentlem start your seedlings!

You could also just use the clear as shown but do a color tarp and tarpaper on the tree. Put flanges on the outer perimeter so pulling the stakes is easier. leave the door opening BUT reinforce it with easily removable struts so to move the structucture you donot have to lift far to move it over the tree.

This is great - but there are no details about how to build the door and keep it closed! That's a pretty crucial step, if you want it to function! Also, it would be nice to have some info on how you make your flaps, etc.

Those pieces of info would make this about perfect. Thanks for doing the work to present this!

The offsite link to the monkeyc.org rebar bender illustrations no longer works, but the rebar bender shown here is intuitively obvious:

Take one hunk of railway tie, four honkin' big bolts with large heads, and a four-foot piece of 3/4" plumbing pipe or conduit. Sink the bolts halfway into the railroad tie as shown. My guess is that they're about an inch and a quarter apart. I don't know why the back two are staggered like that, but doubtless there's a reason for it. To use: thread rebar between the bolts. Slide the pipe onto the rebar. Stand on the railway tie. Have your friend stand on the railway tie too. Use the pipe as a long-handled lever to bend the rebar.

Great project. Stapling a second layer of plastic to the inside of the frame would improve its ability to trap heat, though you might have problems with moisture trapped between the layers. Rigging a two-layer door with overlapping flaps would also help keep the greenhouse warm in early spring and late fall.

what is the benefit of creating a dome rather than a simple rectangle? or any shape for that matter? i do understand that the bucky ball shape or dome is potentially really stable, but are there any other benefits to it for use as a green house i mean?

Air flow is supposed to be better in a dome, natural convection, so less temp. differences throughout.. There is also some efficiency in the use of materials. If you have a central standing area with the plants around the outside, you could use a smaller building for the same headroom. An "A" frame building would work in the same manner I suppose. Not necessarily a "better" greenhouse, but I like the idea of teaching the children alternatives to the plain "square" buildings that are so commonly used. Learn to think "outside the box" _pun intended. This also teaches some math and geometrical skills. For an easier to build greenhouse, 1/2"-3/4" PVC pipes can be bowed, and a plastic material draped over them, but this just has so much more style.

Great design - I want to build one of these domes as a greenhouse but have struggled to find the perforated metal strap you used for connectors anywhere in the UK. Can anyone tell me where I can get hold of this stuff in the UK or suggest an alternative way to make the connectors?

There is a slightly less rigid kind of strapping called 'plumbers tape' in the US. The normal use of plumbers tape is: hang a pipe that is being run across a ceiling below joists in a basement, one might take a strip of plumbers tape (that has regularly spaced holes and is 1 to 1.5" or 2 to 5cm wide) to attach to the stringers or joists making a sling to hold the pipe. Attach a strip like this every couple of joists or few feet (meter or so) to keep the pipe close to the joists.